Evaluation of anti-corrosive properties of epoxidized rubber and siloxane hybrid coatings

Graphene oxide (GO)-modified polypyrrole (PPy) coatings were obtained by electrochemical methods in the presence of the anionic surfactant, sodium dodecyl sulfate (SDS). The structure, morphology, and electrochemical properties of the coatings were assessed by Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM) and cyclic voltammetry at varying scan rates, respectively. The properties of the obtained coatings were analyzed with the GO and PPy loadings and electrodeposition mode. The hybrid coatings obtained galvanostatically showed a coarser appearance than those deposited by cyclic voltammetry CV mode and improved performance, respectively, which was further enhanced by GO and PPy loading. The capacitance enhancement can be attributed to the SDS surfactant that well dispersed the GO sheets, thus allowing the use of lower GO content for improved contribution, while the choice of suitable electrodeposition parameters is highly important for improving the applicability of GO-modified PPy coatings in energy storage applications.

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Hydrothermal synthesis of nanocrystalline hydroxyapatite–graphene nanosheet on Ti-6Al-7Nb: mechanical and in vitro corrosion performance

Journal of Materials Science Materials in Medicine ◽

10.1007/s10856-021-06514-w ◽

2021 ◽

Vol 32 (4) ◽

Author(s):

Oktay Yigit ◽

Burak Dikici ◽

Niyazi Ozdemir

Keyword(s):

Hydrothermal Reaction ◽

Hybrid Coatings ◽

Stoichiometric Ratio ◽

Corrosion Performance ◽

Graphene Nanosheet ◽

Graphene Layers ◽

Nanocrystalline Hydroxyapatite ◽

One Step ◽

Nano Size

AbstractThe hybrid coatings containing the graphene nano-sheet (GNS) and nano-hydroxyapatite (nHA) phases have been successfully synthesized on Ti6Al7Nb alloys by a one-step hydrothermal method. The hydrothermal reaction was carried out for 24 h at 200 °C. The GNS ratio has been altered as 1, 3, 5 and 7 wt.% in the coatings and, the results have compared with non- GNS containing coatings. The effect of the GNS ratio on the microstructure, hardness, and in vitro corrosion responses has been investigated in detail. The characterizations of the coatings were carried out by SEM, EDS, AFM, XRD and, FTIR. The corrosion behavior of the hybrid coatings was compared in Kokubo’s solution at 37 °C by using potentiodynamic polarization tests. The results showed that the hydroxyapatite phases were deposed on the graphene layers with nano-size nucleation with its Ca/P stoichiometric ratio. The best hydrophilicity (~52°) property has been obtained in nHA/3GNS coatings. In addition, the corrosion rates of coatings increased in the following order: nHA/3GNS < nHA/1GNS < nHA/7GNS < nHA/5GNS < only nHA.

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Anti-corrosion properties of oligoaniline modified silica hybrid coatings for low-carbon steel

Synthetic Metals ◽

10.1016/j.synthmet.2017.11.015 ◽

2018 ◽

Vol 235 ◽

pp. 61-70 ◽

Cited By ~ 16

Author(s):

Yuwei Ye ◽

Dawei Zhang ◽

Zhiyong Liu ◽

Wei Liu ◽

Haichao Zhao ◽

...

Keyword(s):

Carbon Steel ◽

Low Carbon Steel ◽

Hybrid Coatings ◽

Low Carbon ◽

Modified Silica ◽

Corrosion Properties ◽

Silica Hybrid

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Diamond Machinable Sol-Gel Silica Based Hybrid Coatings for High Precision Optical Molds

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.438.65 ◽

2010 ◽

Vol 438 ◽

pp. 65-72 ◽

Cited By ~ 6

Author(s):

Andreas Mehner ◽

Ju An Dong ◽

Timo Hoja ◽

Torsten Prenzel ◽

Yildirim Mutlugünes ◽

...

Keyword(s):

Injection Molding ◽

High Precision ◽

Sol Gel ◽

Processing Parameters ◽

Hybrid Coatings ◽

Optical Elements ◽

Optical Components ◽

New Approach ◽

Free Silica ◽

Gel Processing

The demand for high precision optical elements as micro lens arrays for displays increases continually. Economic mass production of such optical elements is done by replication with high precision optical molds. A new approach for manufacturing such molds was realized by diamond machinable and wear resistant sol-gel coatings. Crack free silica based hybrid coatings from base catalyzed sols from tetraethylorthosilicate (TEOS: Si(OC2H5)4) and methyltriethoxysilane (MTES: Si(CH3)(OC2H5)3) precursors were deposited onto pre-machined steel molds by spin coating process followed by a heat treatment at temperatures up to 800°C. Crack-free multilayer coatings with a total thickness of up to 18 µm were achieved. Micro-machining of these coatings was accomplished by high precision fly cutting with diamond tools. Molds with micro-structured coatings were successfully tested for injection molding of PMMA optical components. The wear resistance of the coatings was successfully tested by injection molding of 1000 PMMA lenses. Hardness and elastic modulus of the coatings were measured by nano indentation. The chemical composition was measured by X-ray photo electron spectroscopy (XPS) as a function of the sol-gel processing parameters.

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